Mini Wallet

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Mini Wallet is a lightweight wallet management system built with Laravel and Vue.js.
It is designed as a technical demonstration to showcase system-level engineering decisions such as safe balance handling, concurrency control, atomic transactions, background job processing, and real-time updates using modern web technologies.

This project includes full setup instructions, environment configuration, and steps to run the application locally.

🏗 Key Engineering Decisions

Scalable Balance Management

User balances are stored directly on the user record instead of being calculated from the transaction history.
This design keeps balance lookups fast and predictable, even as the number of transactions grows significantly.

Concurrency Safety

Database transactions combined with row-level locking are used to prevent race conditions and double-spend scenarios when multiple transfers are processed at the same time.

Atomic Transfers

Each money transfer — debiting the sender, crediting the receiver, and recording the transaction — is executed as a single atomic operation, ensuring data consistency at all times.

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✨ Features

• User Authentication
  Login, Registration with Email Verification, Forgot Password, Logout

• Wallet Balance Management
  Add balance to wallet

• Send Money to Other Users
  Searchable by name or email address

• Real-Time Updates
  Powered by Pusher

• Background Job Processing
  Redis queues for async tasks

• JWT Authentication

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🚀 Live Demo

URL: http://13.61.248.128

🔐 Demo Credentials

User Alpha

• Email: user.alpha@demo.app
• Password: mini@Wallet025

User Beta

• Email: user.beta@demo.app
• Password: mini@Wallet025

User Gamma

• Email: user.gamma@demo.app
• Password: mini@Wallet025

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🧪 How to Test (Quick & Easy Guide)

Follow the steps below to test the Mini Wallet application.

1️⃣ Log in with two users

• Open two different browsers
  (Example: Chrome & Edge, or one normal window and one Incognito window)

• Log in as:

  • User Alpha in the first browser
  • User Beta in the second browser

• If the wallet balance is low, use Add Balance to add funds.

2️⃣ Send money from User Alpha to User Beta

• From User Alpha’s account, send some money to User Beta
• After sending:
  • The transaction should appear immediately
  • User Alpha’s wallet balance should be reduced

3️⃣ Verify User Beta’s balance (Real-Time)

• Check User Beta’s account
• You should see:
  • The incoming transaction
  • The updated wallet balance
• ⚡ No page refresh is needed — updates happen in real time

4️⃣ Send money back to User Alpha

• From User Beta’s account, send money back to User Alpha
• This confirms two-way (peer-to-peer) money transfers work correctly

5️⃣ (Optional) Test with a third user

• Log in as User Gamma to test with an additional account

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🛠 Installation Guide

⚙️ Requirements

Component	Version
PHP	8.2+
Composer	Latest
PostgreSQL	18+
Redis	Latest
Node.js	22+
npm	10+

Clone the repository and run the following commands in order:

# Copy environment file
cp .env.example .env

# Install PHP dependencies
composer install

# Generate application key
php artisan key:generate

# Generate JWT secret
php artisan jwt:secret

# Update .env with DB, Redis, Mail, and Pusher credentials

# Run database migrations
php artisan migrate

# Start Redis queue worker
php artisan queue:work redis --tries=3

# Start Laravel development server
php artisan serve

# Install frontend dependencies
npm install

# Build frontend assets
npm run dev     # Development
npm run build   # Production